Pressure sensitive devices such as rupture discs and rupture panels have in the past been fitted with monitoring devices to indicate when the disc or panel has ruptured. These devices have typically included electrical switches which are mechanically tripped by the rupturing of the disc or panel. Mechanically tripped electrical switches have proven unsatisfactory under conditions of extreme heat, and when used in volatile or corrosive environments. Insulation and solder joints, for instance, of mechanically operated electrical switches may melt when subjected to temperatures higher than 700.degree. F. The materials in a mechanical switch are subject to deterioration when surrounded by corrosive fluids, and the use of electrically dependent switches often produces sparking between the leads of the switch, which could detonate an explosion when used near highly volatile fluids.
A monitoring apparatus for pressure sensitive devices is needed that is reliable and safe to use under conditions of high temperature, and in corrosive or volatile environments.